diff --git a/core/modules/system/tests/modules/dialog_renderer_test/src/Form/TestForm.php b/core/modules/system/tests/modules/dialog_renderer_test/src/Form/TestForm.php
index 58436a46ad..dbe9e96797 100644
--- a/core/modules/system/tests/modules/dialog_renderer_test/src/Form/TestForm.php
+++ b/core/modules/system/tests/modules/dialog_renderer_test/src/Form/TestForm.php
@@ -11,14 +11,14 @@
 class TestForm extends FormBase {
 
   /**
-   * {@inheritDoc}
+   * {@inheritdoc}
    */
   public function getFormId() {
     return "dialog_renderer_test_form";
   }
 
   /**
-   * {@inheritDoc}
+   * {@inheritdoc}
    */
   public function buildForm(array $form, FormStateInterface $form_state) {
     return [
@@ -37,7 +37,7 @@ public function buildForm(array $form, FormStateInterface $form_state) {
   }
 
   /**
-   * {@inheritDoc}
+   * {@inheritdoc}
    */
   public function submitForm(array &$form, FormStateInterface $form_state) {
 
diff --git a/core/modules/system/tests/src/Functional/Ajax/OffCanvasDialogTest.php b/core/modules/system/tests/src/Functional/Ajax/OffCanvasDialogTest.php
index a913275870..15a64505b0 100644
--- a/core/modules/system/tests/src/Functional/Ajax/OffCanvasDialogTest.php
+++ b/core/modules/system/tests/src/Functional/Ajax/OffCanvasDialogTest.php
@@ -52,7 +52,6 @@ public function testDialog($position) {
           'draggable' => FALSE,
           'drupalAutoButtons' => FALSE,
           'drupalOffCanvasPosition' => $position ?: 'side',
-          'buttons' => [],
           'dialogClass' => 'ui-dialog-off-canvas ui-dialog-position-' . ($position ?: 'side'),
           'classes' => ['ui-dialog-content' => 'drupal-off-canvas-reset'],
           'width' => 300,
diff --git a/core/tests/Drupal/Tests/Core/Ajax/OpenOffCanvasDialogCommandTest.php b/core/tests/Drupal/Tests/Core/Ajax/OpenOffCanvasDialogCommandTest.php
index a53e10f1ec..c1fe42dd35 100644
--- a/core/tests/Drupal/Tests/Core/Ajax/OpenOffCanvasDialogCommandTest.php
+++ b/core/tests/Drupal/Tests/Core/Ajax/OpenOffCanvasDialogCommandTest.php
@@ -32,7 +32,6 @@ public function testRender($position) {
         'resizable' => 'w',
         'draggable' => FALSE,
         'drupalAutoButtons' => FALSE,
-        'buttons' => [],
         'dialogClass' => 'ui-dialog-off-canvas ui-dialog-position-' . $position,
         'classes' => ['ui-dialog-content' => 'drupal-off-canvas-reset'],
         'width' => 300,